The present invention relates generally to closures for optical fiber splices and connections. More specifically, the invention relates to panel assemblies for use within such closures that include at least one coupler cassette. In another aspect, the invention relates to a fiber optic closure for splitting optical fibers and effecting splice-type and sleeve-type optical fiber connections, and for managing the optical fibers and connections associated therewith.
Closures are used to protect connection s made between the optical fibers of fiber optic cables. Closures are often aerially located along a telephone drop line and allow connections between the telephone company""s main service line and drop lines, which provide phone service to one or more subscribers. Fiber optic closures are used to house the connections made to interconnect the optical fibers of the service line to the optical fibers of the drop lines.
Conventional fiber optic closures are constructed to facilitate the management and protection of fiber-to-fiber splices. For example, many closure designs incorporate splice trays to assist a craftsperson in forming a splice connection between two optical fibers. Once all such splices are made, the outer housing of the closure is secured around the splice trays to protect the splices from weather, infestations, animals and other hazards.
One problem with conventional fiber optic closures is that they are designed to primarily, if not exclusively, house splices to the exception of other types of connections that might be made between optical fibers. With conventional splice-type closures, a pair of fiber optic cables, which contain several individual optical fibers, cannot be readily connected to one another. A craftsperson must strip the insulation cover off of each of the cables and then perform a splice for each pair of individual optical fibers to be joined. Thus, a significant advantage would be obtained by providing a fiber optic closure that is useful for forming and protecting non-splice-type connections as well as splice-type connections. Specifically, it would be advantageous to provide a fiber optic closure that allows sleeve-type connections to be made and protected in addition to splice-type connections.
Conventional closures also lack the capability to split a single optical fiber into two or more optical fibers. It is becoming increasingly necessary in fiber optic networks for a feeder, or express, cable to be connected with multiple drop cables so that service may be supplied to several customers simultaneously. Thus, it would be particularly advantageous to further provide a closure with the capability to split a single optical fiber into two or more optical fibers.
A related problem with current fiber optic closures is that of management of the fiber optic cables and optical fibers. In actual use, a closure contains a great many fiber optic cables and individual optical fibers that are densely packed together. Efforts have been made to provide a means for organizing these fibers and cables. For instance, splice closures are known that incorporate multiple panels to assist in the layout of the individual optical fibers. (See U.S. Pat. No. 5,323,480 entitled xe2x80x9cFiber Optic Splice Closure,xe2x80x9d and U.S. Pat. No. 5,602,954 entitled xe2x80x9cElectrofit Fiber Optics Butt Splice.xe2x80x9d) Currently, however, there is no acceptable system for orderly management of optical fiber splice-type connections as well as optical fiber sleeve-type connections. The fiber management problem extends to, and is obviously exacerbated, in closures wherein a single optical fiber is split into two or more optical fibers. As previously noted, such closures are commonly required when an express cable services multiple drop cables for distribution to several individual businesses or dwellings simultaneously.
The invention provides a fiber optic closure for overcoming the disadvantages of the prior art. In a preferred embodiment, a fiber optic closure is shown and described that has a panel assembly with several planar panels affixed to one another in a hinged manner. The panel management assembly further includes a storage bay that is sandwiched between a pair of optical fiber connection management assemblies.
Each optical fiber connection management assembly includes a panel that supports one or more sleeve connector arrays within which sleeve connectors may be inserted to create fiber optic connections. The panel assembly also provides a conventional splice panel having splice holders within which splice connections are established.
It is preferred to position the splice panel directly adjoining the sleeve connector panel since this will allow a craftsperson to easily form custom sleeve connections within the closure by splicing connectors onto selected optical fibers using the splice panel and then interconnecting the connectors with other connectors using the sleeve connector panel.
A further exemplary splice closure is described and shown that incorporates at least one coupler cassette within the optical fiber connection management assembly. Each coupler cassette is utilized to split a single optical fiber into two or more optical fibers. The coupler cassettes may be conveniently installed and removed from the closure. Accordingly, the coupler cassettes provide an effective means for splitting preselected input optical fibers into predetermined number of output optical fibers to be connected by a field craftsman at the time of installation, or at a later time, to multiple drop cables. The coupler cassettes are generally rectangular enclosures with removable covers that house conventional splitter components and splice tube holder therein.